... region (region-7.5) [xmmsas_20041122_1834-6.1.0] . Meta Index / Home Page This section documents the parameters recognized by this task (if any). Parameter . ... Reference event file used to define the coordinate system for the source and background regions. ... If operationstyle =`single', the task looks in this parameter for the row number of the source list ( after the list is filtered via expression ) for which to construct source and local-background event-extraction regions. srcidcol . ...

... The sky background can contribute significant Poisson noise in broad and medium band filters, and must be taken into account during noise calculations. The actual sky brightness depends on the heliocentric ecliptic coordinates (latitude and longitude) in a manner summarized in Table 6.3 . ... For many targets LOW-SKY will have minimal impact on the observing efficiency. ... Table 6.4 shows approximate sky count rates for the WFC and PC1 for filters with significant sky count rates. ...

... This paper describes the main algorithms used by the Einstein Level One processing to create the exposure masks and the background maps for Einstein IPC images, and how these algorithms were recreated in the IRAF environment. Our goal was to recreate the algorithms used by the Level One Processing to create exposure masks and background maps for Einstein Image Proportional Counter (IPC) data (cf. sections 2.5 and 2.7 of Harnden et al. ...

In this gallery are many images of Low Surface Brightness Galaxies which have recently been discovered and analyzed. ... The central surface brightness of this galaxy is 24.28 . Malin 2 This galaxy is another huge disk galaxy with a scale length of 15 kpc and a redshift of 15000 km/a. The high surface brightness knot in one of its spiral arms actually has the same color, luminosity and H-alpha equivalent width as the entire Large Magellanic Cloud . ... Truly it is a Low Surface Brightness Galaxy. ...

Once students get the hang of it, they can find and measure the brightness of Delta Cephei in a few minutes. ... of Delta Cephei . ... Oct. ... The following table lists the measurements of Delta Cephei made by one amateur astronomer in autumn 1990. ... 4.0 . ... This activity is a simplified version of one that appeared in Hands-On Astrophysics, a series of activities prepared by the American Association of Variable Star Observers with support from the National Science Foundation. << previous page | ...

. Please standby and you will be automatically connected to the new location of the unframed Supernova page. Or, click on the link above. If you have questions or problems, please email me at David Bishop dbishop@vhdl.org . Last modified: Mon Aug 27 12:40:15 EDT 2001

Appendix C Radiative Transfer for a Two-Level System This appendix details how to derive the total column density of a linear rigid-rotor molecule, such as CO, from the observed brightness of its rotational transition. ... C.2 Radiative Transfer for a Two-Level System I now consider emission in a two-level system from an upper J + 1 (denoted `u') to lower J (denoted `l') state. ... Spontaneous emission is controlled by the A coefficient, with a rate Aul nu . ... Tex exp(-31. ...

THE PHOTOMETRIC RESEARCHS OF THE MERCURY'S SURFACE BY MEANS OF DIGITAL MODELS. ... The surface brightness of Mercury was measured Danjon (1933, 1949, 1953) and Harris (1961) in phase angle 3o-123o. The analysis of the various data of the integral photometric gives the results of determination of the main photometric constants for Mercury. ... THE PHOTOMETRIC RESEARCHS OF THE MERCURY'S SURFACE: S.G. Pugacheva The surface brightness of the Mercurian images was established on the geologic map Mercury. ...

... 389Voges+ IX/10A ROSAT All-Sky Bright Source Catalogue (1RXS) (Voges+ 1999) ================================================================================ The ROSAT all-sky survey bright source catalogue. ... At a brightness limit of 0.1cts/s (8,547 sources) the catalogue represents a sky coverage of 92%. Broad band images are available for a subset of the flagged sources from http://wave.xray.mpe.mpg.de/rosat/catalogues/rass-bsc . ... 0 Source countrate (4) 70- 78 E9.3 ct/s e_Count ?= ...

... They worked out that first magnitude was on average 100 times brighter than the 6th magnitude star. ... This formed an equation of apparent magnitude Mv which is: Mv = -2.5 log f + constant were f is the flux of that star f = ( counts/ exposure) The images that we worked on were taken by the Polar Bear Telescope. ... One of these being that it will be combined with standard stars, which will be used to identify the area of stars and to also help identify other stars within the image. ...

... We are using Canadian Galactic Plane Survey l 74.2њ, -3.6њ < b This poster gives preliminary results for a full-fledged analysis of the gas properties and distribution of HISA features in the CGPS. ... where T ON and T OFF are observed brightnesses on and off the HISA feature, T S is the spin or excitation temperature of the HISA gas, tau is its optical depth, T C is the continuum intensity, and p is the fraction of H I emission lying behind the HISA feature. ... GIF | ...

... Imagine that for every pixel in the color image, you take its luminance value (that's how bright it appears). ... In the end, you will have a histogram which counts how many times each luminance value appears in the image (that histogram can be used to analyze the distribution of the luminance values in the image). ... For the watermark effect, we want to use the same value that we used in the Stretch Contrast step, so that the lightest color will be in fact white (255), and nothing will get clamped...

... X Ray Moon . ... In this digital picture, pixel brightness corresponds to x-ray intensity. Consider the image in three parts: the bright hemisphere of the x-ray moon, the darker half of the moon, and the x-ray sky background. ... Still, the few x-ray photons which seem to come from the moon's dark half are currently thought to be caused by energetic particles in the solar wind bombarding the lunar surface. ... Publications with keywords: Moon - x-ray background - cosmic rays - X-ray . ...

The night sky brightness, together with number of clear nights, seeing, transparency, photometric stability and humidity, are some of the most important parameters that qualify a site for front-line ground--based astronomy. ... Night sky at ESO-Paranal (Chile). ... Night sky brightness data . ... UBVRI night sky brightness at ESO-Paranal during sunspot maximum (A 2003, PDF) . ... The Dancing Sky: six years of night sky observations at Cerro Paranal (Starlight 2007 conference proceedings, PDF) . ...

... Problem 5. ... See figure 1 for the light curve of these narrow Nitrogen lines. ... Figure out the behaviour of each parcel of gas, and then add them all up to find the light curve. 5.4 (3pts) Using expression from problem 5.2, derive the expression for the time after SN explosion date, when the first light from the ionised ring reaches Earth. Using the expression from problem 5.2, derive the expression for the time after SN explosion date when the maximum brightness of the ring occurs. ...

Measurement of Sky Brightness at the Iranian National Observatory Davoud Afshari1 and Sadollah Nasiri1,2 1Physics Department, Zanjan University, Zanjan 45195-313, Iran; Institute for Advanced studies in Basic Science (IASBS), Zanjan 45195-1159, Iran; Measurement of light pollution 2 Introduction Among 34 candidate sites at the central part of the country, 5 sites namely Garkesh (in Kashan ), Kolahbarfi(in Kashan ), Deynava (in ... One of these is light pollution. ...

... Outline of the BTF paper by Erwin de Blok (25-2-2002) ----------------------------------------------------- * Description of sample * Data and corrections * Descriptions of method to measure line widths * Description of method to measure inclinations * Corrections to linewidths and magnitudes (inclination, random motion, instrumental resolution, extinction) * Corrections to recession velocities (to Local Group frame, also POTENT etc for nearby galaxies) * Describe B-band ...

... RJMCMC Similar to Richardson Green 1997 Knowledge of the PSF makes things easier Insensitive to e.g. posterior for ten sources with = 3: Number of Components 9 10 11 12 0.141 0.222 0.220 0.157 0.022 0.029 0.027 0.021 Mean SD 7 0.029 0.018 8 0.058 0.019 13 0.082 0.014 Simulated Data Source region (2 SD) is about 28% of the area and contains about 41% of the observations Positions (-2, 0), (0, 1), (1.5, 0) with intensities ... Approximate the number of sources (2 in this case) 2. ...

... It is found that the correlation coefficients between these two parameters calculated separately inside and outside the sunspot formation zone ±30 have cyclic variation and occur in anti-phase. This suggests different mechanisms of formation of the corona in the fields of small, medium, and large scales. ... The relationship between the coronal green line brightness (CGLB) and the magnetic field strength (MFS) has been investigated by constructing the corresponding synoptic maps for the 1977-2001. ...

Next: Gravitational Wave Background from Previous: Galactic Gravitational Wave Background . ... It is intuitively clear that at frequencies above the critical ones for our Galaxy, one will detect rare bright jerks produced by coalescing white dwarfs   (at a rate of 1 per 100 year) and NS (at a rate of 1 per - year) in our Galaxy, against a background of the extragalactic stochastic GW. ... Firstly we consider GWB from close individual galaxies, and then will discuss overall extragalactic GWB. ...